this post was submitted on 01 Jun 2024
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Taken on a small group of Islands in the Oslo fjord, called Hvasser. A 15 meter peice of fabric playing in the wind, scanned right to left in 21 seconds. Got really lucky with the clouds this time, allowing a single beam of sunlight in as a highlight.

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[–] hhhyperfocus 1 points 1 month ago* (last edited 1 month ago) (2 children)

@Leavingoldhabits Hi again, can I ask you some technical questions? I'm struggling modify my scanner. I've removed the clips holding the PCB, and I even made a test scan in that state, and it still worked. Then I spent hours milling out the pinhole array. But when I assembled it again, I get weird scans.

I have modified two different scanners. LiDe 110 - I get a tall narrow PNG file with some digital noise. I assumed I damaged the sensor, or a ribbon cable or something, so I shelved it, and looked for another scanner.

N650U - I took more care modifying this one. I get a full width PNG file, but it has a narrow strip of white on one side, and black everywhere else. I wonder if it is related to the initial calibration that it does before scanning. I left the LED in tact, but I removed the prism, so maybe it's lighting up just that one end of the calibration strip?

Did you have any calibration problems? Have you encountered anything like this? Do you have any advice?

Thanks

[–] Leavingoldhabits 1 points 1 month ago (2 children)

Hi!

I’ve only ever managed to get the lide30 to play nice. I have destroyed one 110 and two 220-scanners in my efforts to build a more versatile rig.

What happens if you drop the prism back in?

I’ve also speculated about there being som calibration and automatic gain control going on in these newer models. I believe it could be used to normalize the values coming off of the individual sensor segments.

On my latest attempt at a 220 scanner, I actually built a small dimmable LED circuit that I attached externally to try and influence the calibration I thought was happening, but there was a disappointing lack of results. Come to think of it, I still have that rig laying around somewhere, and the experiment may have been flawed, I’ll have a look next time I’m at my workshop. I’ll let you know what I find.

I know that rig is at least functional, as objects placed directly onto the glass renders crude shadows on the scans.

That’s the long answer, the short answer is no, I don’t have any tips, maybe aside from working on fooling the possible calibration somehow.

[–] hhhyperfocus 1 points 1 month ago (1 children)

I managed to change the image by just shining a torch into it during the calibration and the scan. This is exciting, I might be making progress :-)

[–] Leavingoldhabits 2 points 1 month ago (1 children)

Thats really Cool! Thanks for letting me know, this might be the impetus I needed to go back to working on the 220 camera!

[–] hhhyperfocus 1 points 3 weeks ago (2 children)

So, when I say "change the image", I mean the torch does affect the calibration, in the sense that I get different patterns of stripes based on the position of the torch, but it's still just outputting stripes.

Here are two scans I made by waving the torch around randomly during the calibration, then resting the torch on the glass.

For some reason each pixel is just outputing the same brightness for the whole duration of the scan, except for that black spot where the torch is, which is weird.

[–] hhhyperfocus 1 points 3 weeks ago

So, I re-installed the prism, luckily it just slots back in. I'm not sure if it helped at all, I still get the much the same result most of the time.

I did manage to get this result. It's black at the top because the lid was closed. I opened the scanner half way thru, and the scan turned white. Then I waved the torch over the sensor and got a definite zigzag. And there's a hint of grey in the middle, which is encouraging.

So, the sensor is still working, it's responding to light, just not in a usable way.

[–] hhhyperfocus 1 points 1 month ago

Ok, thank you.

[–] hhhyperfocus 1 points 1 month ago

Scanned with a modified N650U